Cyanogenesis variation in the Turnera sidoides L. polyploid complex (Turneraceae)

Abstract

This study constitutes the first investigation of cyanogenesis variation within the Turnera sidoides autopolyploid complex. The qualitative and quantitative analysis carried out in 38 populations showed that the five subspecies of the complex are cyanogenic, although the levels of cyanide released varied both between and within subspecies. Between the subspecies, carnea, holosericea and integrifolia showed higher values of HCN released than subspecies pinnatifida and sidoides. Within subspecies, there is a tendency toward an increment of mean cyanide values with ploidy levels and different hypotheses are considered in order to explain this variation. The study of cyanogenesis in populations from different geographical areas cultivated under uniform greenhouse conditions showed that, in the widespread subspecies pinnatifida, HCN variation may also reflect the action of different selection pressures, since populations having dissimilar cyanide levels grow in different phytogeographical provinces with different climatic regimes. On the other hand, the fact that the variation of HCN released was greater between populations from different geographical areas than that observed between diploid and tetraploid populations of the same area provides additional evidence for the multiple origins of polyploids of the T. sidoides complex. © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003, 141, 85–94.

Chemical and physical plant defence across multiple ontogenetic stages in a tropical rain forest understorey tree

“…However, Manihot esculenta (McMahon et al . 1995), Eucalyptus yarraensis ( n = 170; Goodger & Woodrow 2002) and the Turnera sidoides species complex ( n > 190; Solís Neffa et al . 2003) are also known for their complete absence of acyanogenic individuals and recent work by Miller et al .…”

“…Hughes 1991;Schappert & Shore 1995). However, Manihot esculenta (McMahon et al 1995), Eucalyptus yarraensis (n = 170; Goodger & Woodrow 2002) and the Turnera sidoides species complex (n > 190;Solís Neffa et al 2003) are also known for their complete absence of acyanogenic individuals and recent work by Miller et al (2004Miller et al ( , 2006 has found that a number of other Australian rain forest trees appears to be uniformly cyanogenic. It may be that the high herbivore pressures in rain forest ecosystems, relative to temperate environments (Coley & Barone 1996), have selected against acyanogenic phenotypes in cyanogenic rain forest species.…”

Constitutive polymorphic cyanogenesis in the Australian rainforest tree, Ryparosa kurrangii (Achariaceae)

“…The majority of plant species where reasonable numbers of individuals have been tested have reported a certain percentage of functionally acyanogenic individuals (e.g. Cooper-Driver and Swain, 1976;Ellis et al, 1977;Dirzo and Harper, 1982;Till, 1987;Hughes, 1991;Schappert and Shore, 1995;Aikman et al, 1996;Pederson et al, 1996;Bazin et al, 1997;Goodger et al, 2002;Gleadow et al, 2003; but see Kakes, 1994;McMahon et al, 1995;Solís Neffa et al, 2003). Locating and testing larger populations of the rare R. kurrangii will be required to confirm if this species has qualitative as well as quantitative polymorphism for cyanogenesis.…”

Estudios Sistemáticos en Turnera (Turneraceae). Iv. Series Leiocarpae, Conciliatae Y Sessilifoliae

“…38621, 38695 y 38754 (Fernández, 1987). Cariotipo: Krapovickas & Schinini 36653 (Solís Neffa, 1996). Distribución: Especie de amplia distribución en el centro y Este de Brasil (Alagoas, Amapá, Amazonas, Bahia, Ceará, Goiás, Maranhão, Mato Grosso, Mato Grosso do Sul, Minas Gerais, Pará, Paraíba, Pernambuco, Piauí, Rio Grande do Norte, Rondonia y Tocantins) norte y este de Bolivia y noreste de Paraguay.…”

“…La variación en la subsp. pinnatifida podría estar relacionada con la presión de selección ejercida por diferentes regímenes climáticos (Solís Neffa & al. 2003).…”